Devising that sort of mash-up, which handles multiple data sources to produce a customized solution, is typically the province of a professional. But the new systems are designed, their creators say, so people with modest technical skills can tailor applications to their needs — while writing little or no code.

For now, the technology is free, as its creators race to sign up customers, extend their franchises and perhaps someday dominate the field. Some of the new systems are aimed at businesses, others at consumers who want to entertain themselves by creating games or ornamenting a blog.